Several core-drilling apparatus are known in which the core of work material is ejected from the drill-forming member at the completion of the drilling operation with the use of a member which is additional to the mandrel and drill-forming members themselves. In U.S. Pat. No. 2,433,058, for example, a knurled collar is grasped to form a plunger which ejects the core of work material from the drill-forming member when the member is retracted over the plunger. In U.S. Pat. No. 2,923,180 and 2,414,133, a spring-loaded member is held in a retracted position until the completion of the drilling operation, and then is used to eject the core of work-material, the drill-forming member. In U.S. Pat. No. 3,978,733, the core of work material is ejected with a hydraulic jack. In U.S. Pat. No. 4,657,445, the core of work material is removed through the top end of the drill.